Scientists are describing Saturn's biggest moon, Titan, as a frigid world of coastlines, wind, mists, and blocks of ice strewn about the landscape. Their first impressions of this hidden world come from data sent back by the European Space Agency's Huygens spacecraft, which landed on the mysterious moon Friday. The space probe has returned enough data to keep researchers busy for months.

An international band of scientists spent a sleepless night poring over a rich trove of Huygens data at the European Space Agency's mission control in Darmstadt, Germany. The space probe relayed the information during its parachute descent toward Titan Friday and for several hours afterward on the surface. Mission manager Jean-Pierre Lebreton, says it begins to unveil a celestial body shrouded by a murky atmosphere.

"I must say after a night of very hard work by all teams, we can now start to see a clearer picture of Titan emerging," he said.

Scientists have been eager to peer into Titan, whose thick atmosphere of nitrogen and methane they believe is similar to that of the young Earth billions of years ago before life appeared. As might be expected, Huygens detected atmosphere-like conditions, such as clouds at 20 kilometers altitude and patches of fog hovering over the surface.

University of Arizona researcher Martin Tomasko says cameras saw what appears to be a shoreline along a dark area with dark channels flowing into it, like a river delta.

"It's almost impossible to resist the speculation that this flat, dark material is some kind of drainage channel, that we're seeing some kind of a shoreline," he said. "We don't know whether this still has liquid in it or whether the liquid has drained away or drained into the surface."

Scientists believe these dark areas on the big Saturn moon are likely to be reservoirs of methane. They also displayed images of rocks up to 30 centimeters wide whose light reflection suggests they are blocks of water ice, darkened a bit by methane and possibly other hydrocarbons.

No one is certain precisely what kind of surface Huygens landed on, but John Zarnecki of Open University in Britain says it penetrated 15 centimeters into a soft material.

"So what we're seeing is, we think - and this is, of course, a very early interpretation - is a material that might have a thin crust followed by a region of relatively uniform consistency. The closest analogs I can give you - and remember these are not suggesting the materials we have hit - are wet sand or clay," he said.

The mission's only technical flaw occurred during Huygens' descent when one of two communications channels malfunctioned. This cut in half the number of images relayed through the U.S. Cassini orbiter overhead, which had carried Huygens to Saturn. The lost channel was a backup carrying mostly data duplicated on the other, but it also was to carry wind data the other channel did not.

The European Space Agency's science director, David Southwood, says the loss of wind information can be made up by observations by a network of radio telescopes on earth. The early indications are that the source of the malfunction was aboard the Cassini mothership.

Despite the problem, Mr. Southwood was ecstatic at the new findings, calling his look at the data an extraordinary experience.

"I thank whatever gods, and please, if you have any gods, please thank them, too,"